One or more DC cooling fans are often employed in power conversion systems to remove heat generated by electronic devices. Cooling fans play an important role in overall system reliability and lifetime.
In most power conversion applications, commercially available cooling fans (e.g., the Beta V, manufactured by Nidec America Corporation of Torrington, Conn.) are included in chassis or power conversion modules manufactured by original equipment manufacturers (OEMs) The fan is often a square box fan with mounting holes located in the four corners of the box. The fan is equipped with an electrical pigtail to accomplish the necessary electrical interconnection to the power conversion module. Typical fan mounting methods involve four machine screws with an equal number of hexagonal nuts ("hex-nuts"), and perhaps lock washers, holding the fan to the frame or cabinet of the power conversion module. Thus to hold a single fan in place, eight, and possibly twelve, hardware parts are required. Often, the required service life of the electronic equipment is greater than the service life of the fan, so field fan replacement is part of routine maintenance. Of course, physical installation of the fan involves properly locating the fan housing in relation to the power conversion module cabinet or chassis, and manually routing the machine screws through mount holes in the fan housing and matching holes in the chassis cabinet. Lock washers must then be placed on the exposed machine screws and the hex-nuts threaded on the machine screws. The installer must then tighten the hex-nuts in place, usually with a screwdriver and a nut driver. As a consequence, multiple parts are required to install a single fan unit, in addition to the labor required to install, align and tighten the machine screws and nuts. When considering applications such as the telecommunications industry, where hundreds of thousands of fans are required to cool power conversion units, the total part count required and cost is obviously very significant.
Accordingly, what is needed in the art is a simpler method of securely mounting a cooling fan in a power conversion cabinet that minimizes part count and installation labor.